Another cross post from the official forums.
Some thoughts on rogue level 100 talents and Death from Above in particular.
One important caveat for the rest of the results in this post. SimulationCraft implements the auto attack loss from Death from Above as an 800ms swing timer pushback. However testing in game suggests that the auto attack pushback caused by Death from Above is closer to 1.1-1.4 seconds.
Pathal’s Results: http://pastebin.com/3hCTcPAb
For this test I tracked the swing timer with a weak aura and attempted to use DfA as close to the end of the swing timer as possible to show the maximum possible loss from DfA and then determined the auto attack loss as the time difference between melee swings minus the 2.47 second swing timer.
With this potentially modeling inaccuracy in mind which may overstate the value of DfA some results.
This shows 4 combat configurations based on the T17M profile. T17M uses Shadow Reflection by default, DfA_no_AR is a modified version of the DfA profile that does not use DfA during adrenaline rush due to energy capping issues.
This shows pretty clearly that DfA is a non-trivial dps loss for combat compared to no talent(~3.5%) due to a combination of factors, most importantly the high energy cost of DfA compared to evis (25 energy vs. 10 energy after relentless strikes is taken into account) results in a reduction of AR uptime (20.69% vs. 22.5%), deep insight uptime (28.28% vs. 33.68%) and killing spree uses (9.5 vs. 10.3). It is not clear how important the auto attack loss since the changed AR uptime confounds energy regen however intuitively is will be most detrimental to combat with its high passive damage compared to the other specs and energy regen that relies on auto attacks.
Assassination has DfA as a minor dps increase over no talent but still not competitive with shadow reflection in the default profile. The underlying issue with DfA for assassination is similar to the issue for combat, both specs get substantial portion of the value of their finishers from side effects rather than direct damage. Combat loses cooldown and BG cycling speed and assassination loses envenom uptime (75.31% vs. 81.04%) due to the energy cost of DfA compared to a regular envenom. Auto attack loss does not seem to be a substantial issue for assassination with ~0.3 auto attacks lost per hand per DfA.
Unlike combat and assassination subtlety has no major side effects on eviscerate. This makes subtlety the best possible spec for DfA and the data bears this out. While DfA is a useful dps increase for subtlety it is outdone by shadow reflection (the default sub profile uses venom rush). Even if DfA showed a slight dps increase for subtlety it would be a hard sell since DfA is by far the hardest of the three talents to use requiring cp and energy pooling and raising all the loss of control and landing in a bad spot issues combat rogues have been complaining about with killing spree for 3 expansions now. Compare this to SR which is effectively a passive talent that is macroed into primary cooldowns.
Reducing the energy cost of DfA to 35 energy like a standard envenom/eviscerate would help DfA be much more competitive for assassination and combat since it would reduce the envenom uptime loss and reduced cycling speed respectively. It would also probably push DfA above SR for subtlety, matching damage with degree of difficulty.
Another possibility would be buffing the AoE pulse portion of DfA to be a useful form of AoE damage. Currently it hits for very little damage and would help give the talent a niche on the tier. One problem with the rogue 100 tier in general is both SR and DfA are primarily single target dps talents without any other major niche, this means that the weaker talent between the two will get left by the wayside. Increasing the AoE pulse damage of DfA would give DfA a niche beyond single target which may keep it useful even if the single target damage is lower than that of SR.
In a similar vein Pathal suggested in #ravenholdt that the AoE pulse could proc poisons, this would grant a larger benefit to combat and assassination than subtlety and would increase the effective damage of the AoE pulse without having to buff its damage.